Concrete

building · materials · construction · chemistry

Made from mixing rocks. Concrete is created by combining small rocks and sand with a special glue called cement. When you add water to this mixture, it turns into a wet paste that can be shaped into almost anything.

Gets harder over time. Fresh concrete starts soft and squishy, but after a few days it hardens into stone-like material. The cement acts like a superhero glue that bonds all the rocks together as it dries.

The world's favorite building material. Concrete is used more than almost any other material on Earth. It's in roads, buildings, bridges, dams, and sidewalks everywhere you look.

Second most used substance ever. Only water is used more than concrete around the world. Billions of tons of concrete are made every single year to build our cities and infrastructure.

Different from asphalt. Concrete has a cement binder that makes it super hard and durable, while asphalt uses a sticky substance called bitumen instead. That's why concrete lasts longer and works better for buildings.